This invention relates to a ribbon cartridge having a biasing member for positioning an ink ribbon to print position for use in a printer. More particularly, this invention relates to an apparatus for uniformly restricting the running position of an ink ribbon to a print head of the printer.
In general, a carrier is provided within the printer and moveable in the printing direction. A print head is mounted on the carrier and a ribbon cartridge is removably, interchangeably and rotatably fitted thereto. Accordingly, under operating conditions, it is necessary to correctly position the ribbon cartridge so that the ink ribbon runs at the correct position opposed to the printer head.
FIG. 1 is a side view of a primary part of a conventional printer with a mounted ribbon cartridge.
The printer includes a carrier 1 and a platen 3. The carrier 1 is driven along the platen 3 normally using a wire and pulling arrangement such that the carrier 1 can reciprocably move parallel to and along the platen 3. The carrier 1 is moveable along a shaft 5. The above components and assembly of the printer are mounted and held in a frame (not shown). The shaft 5 is connected to and mounted between side walls (not shown) of the frame. A print head 7 is fixed to the carrier 1. The carrier 1 has upwardly extending pole members 9 located at both sides of the carrier 1. Each pole member 9 is formed with a through hole 11 at the top end thereof. A ribbon cartridge 13, loaded with an ink ribbon 15, has a support member 17 located at both sides of the ribbon cartridge 13. The cartridge 13 is axially and pivotally mounted by the support members 17 being positioned in through holes 11 formed in pole members 9. At the sides of the end opposite to the pivoting end of the cartridge 13 and in the rotating range of the cartridge, a pair of stoppers 19, 21 are provided for positioning the ink ribbon 15 to the print head 7. The ribbon cartridge 13 is biased in the direction of arrow mark "A" shown in FIG. 1 by a separate plate spring 23 fixed to the carrier 1, such as by a screw 15. The biasing force of spring 23 urges the ribbon cartridge 13 in such a direction as to engage with the stoppers 19, 21. This type of printer is further disclosed in Japanese Patent Publication (Koukoku) No. 53-12849 issued on May 4, 1978.
In a printer using this type of ribbon cartridge assembly, the separate plate spring 23 is provided to bias the ribbon cartridge 13 and a screw 25 has to be used for fixing such a plate spring 23 to the carrier. Therefore, considerable parts and assembling cost have been required just for providing bias for the ribbon cartridge 13.